There are numerous methods known to those skilled in the art for spinning fibers that can be later formed into a nonwoven web. Many such nonwoven webs are useful in disposable absorbent articles for absorbing body fluids and/or excrement, such as urine, fecal matter, menses, blood, perspiration, etc. Three dimensional fibers are also useful in forming materials that can be stretched in the machine direction, cross direction or in both directions to form webs that can be made into bodyside covers, facings and liners. Manufacturers of such articles are always looking for new materials and ways to construct or use such new materials in their articles to make them more functional for the application they are designed to accomplish. The creation of a web of 3-dimensional, bicomponent fibers wherein the fibers are formed from at least one elastomeric material that can extend in at least one direction can be very beneficial. For example, an infant diaper containing an absorbent layer formed from cellulose pulp fibers interspersed into a web of 3-dimensional nonwoven fibers will allow the absorbent layer to retain a larger quantity of body fluid if the 3-dimensional fibers can extend. Such an absorbent layer can provide better leakage protection for the wearer and may not have to be changed as often. In another example, a spunbond nonwoven facing or liner formed from a plurality of 3-dimensional fibers can provide improved stretch and controllable retraction. Such facings or liners can provide improved fit and better comfort for the wearer of absorbent articles.
A web formed from such 3-dimensional fibers can provide one or more of the following attributes: improved fit, improved loft, better comfort, greater void volume, softer feel, improved resiliency, better stretch and controlled retraction.
The exact method utilized in forming a nonwoven web can create unique properties and characteristics in the web. Now a 3-dimensional fiber has been invented that exhibits exceptional elongation properties in at least one direction. A web made from such fibers has also been invented.
Briefly, this invention relates to a 3-dimensional fiber that exhibits exceptional elongation properties in at least one direction. The 3-dimensional fiber is formed from a first component and a second component. For example, the first component can form the core of the fiber and the second component can form a sheath around the core. The first component is capable of being stretched and has a recovery percentage R1. The second component is also capable of being stretched and has a recovery percentage R2, wherein R1 is higher than R2. The first and second components cooperate to form a linear fiber having an initial length that can be stretched at least 50%. The stretched fiber is then allowed to retract to a length of from about 5% to about 90% of its stretched length into a 3-dimensional fiber. The retracted 3-dimensional fiber exhibits the ability to be elongated at least 250% in at least one direction before the fiber becomes linear. A web made from such fibers has also been invented.